Thiourea compound

ABSTRACT

New compounds having the formula (HO-alkylene-(O-alkylene)xNH2C S are chain extenders for polyurethanes.

United States Patent Edwards et al.

[ 51 Aug. 1,1972

[5 4] THIOUREA COMPOUND [72] Inventors: Gayle Dameron Edwards, Nederland; Philip Hotchkiss Mos, Austin,

both of Tex.

[73] Assignees Jefferson Chemical Company, lnc.,

Houston, Tex.

[22] Filed: May 26, 1969 21 Appl. No.: 827,989

[52] U.S. Cl. ..260/552 R, 260/775 AQ [51] Int. Cl ..C07c 157/06 [58] Field of Search ..260/552 R [56] References Cited UNITED STATES PATENTS 3,168,560 2/1965 Levis et al ..260/552 R 2,674,619 4/1954 Lundsted ..260/552RX FOREIGN PATENTS OR APPLICATIONS 804,299 ll/l958 Great Britain Primary Examiner-Leon Zitver Assistant Examiner-Michael W. Glynn Attorney-John R. Kirk, .lr., H. G. Jackson and Terrence Dean Dreyer [57] ABSTRACT New compounds having the formula [HO-alkylene- (O-alkylene),Nl-l] C S are chain extenders for polyurethanes.

1 Claim, No Drawings THIOUREA COMPOUND BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains to new thiourea compounds. 2. Description of the Prior Art Robert Gehms US. Pat. No. 3,301,823 (1967) teaches the use of dihydrazino-di-s-triazine compounds as chain extenders for polyurethanes.

SUMMARY OF THE INVENTION DESCRIPTION OF THE PREFERRED EMBODIMENTS New compounds useful as chain extenders for polyurethanes are prepared by reacting polyglycol amines of the formula NH (CHR,CHR O),H, where R and R are hydrogen or alkyl groups and x is an integer from 1 to 4, with carbon disulfide.

EXAMPLE I Hydroxyethoxyethylamine (315 g., 3.0 mole) and 300 g. of water were placed in a two liter three-neck round bottom flask equipped with a mechanical stirrer, reflux condenser, thermometer and gas inlet. Carbon disulfide (122 g., 1.6 moles) was added over a 30 minute period with stirring and cooling with a water bath. The reaction mixture was stirred and heated at 97-98 C. until the production of H 8 had essentially ceased (*9 hours). A small flow of nitrogen was passed MW s OH Number %N Osmometer Found & 659 l 1.1 252 Calculated for (NHCHzCHzO CHzCHz QH):

Substituted thioureas exist in the sit 1t N=CNlllt form to a large extent and the OH number of the product supports this structure (OH number calculated for three reaction hydrogens 670). In the form, the compounds of this invention can act as crosslinking agents for urethanes. For the purposes of this invention, the words chain extenders define both linear chain extender or cross-linking properties of the compounds of the invention.

EXAMPLE II The l,3-bis(2,2-hydroxyethoxyethyl)-2-thiourea of Example I is a chain extender for a polyurethane. In the table below, the properties of a polyurethane cured in the presence of l,3-bis(2,2-hydroxyethoxyethyl)-2- thiourea are compared to a polyurethane cured without 1 ,3-bis( 2,2-hydroxyethoxyethyl )-2-thiourea. The polyurethane cured without l,3-bis (2,2-hydroxyethoxyethyl)-2-thiourea is labeled Blank in the table.

The polyurethane was made by blending a 3,000 molecular weight triol (900 grams) and clay filler (660 I grams) until they were thoroughly mixed. Trimethylolpropane (6.0 grams) was then added and this mixture was heated under vacuum to 120 C. to remove anY water. The mixture was then cooled to C. at which point l,3-bis(2,2-hydroxyethoxyethyl)-2-thiourea was added. After cooling to room temperature (26 C.) a 650 gram portion of the mixture was mixed with sufficient polymeric isocyanate to produce an isocyanateto-hydroxyl ratio of 1.15. The polymeric isocyanate had a functionality of about 2.7-2.8. After adding dibutyltin dilaurate catalyst and stirring rapidly for 30 seconds, the mixture was cast in an aluminum mold and allowed to cure at room temperature.

The chain extender properties of l,3-bis(2,2-hydroxyethoxyethyl)-2-thiourea are illustrated by the increased elongation and the lower compression resistance shown in the data of the table below. The elastomeric polyurethane containing l,3-bis(2,2- hydroxyethoxyethyl)-2-thiourea has lower Shore A durometer hardness and about 20 percent higher tensile strength than the blank. Also, the Component B in the table has a lower viscosity when l,3-bis(2,2-hydroxyethoxyethyl)-2-thiourea is included. The lower viscosity makes the component more fluid, therefore, more workable.

The viscosity of the component B was run on a Crookfield Model LVT Viscometer, using a number 4 spindle. The spindle speed was 12 revolutions per minute for the reading shown in the table and the tem perature of the component B was 25 C.

Tensile uen u z pounds per square Having thus described our invention, we claim:

inc (AS D-4l2-64T. die C) 921 780 Elongatiomqb l. 1,3 bis(2,2 hydroxyethoxyethyl) 2 thiourea of the (ASTM D 412-64T, die 65 3s formula Tear strength, pounds per lineal inch (ASTM D 624-54, die C) 47 42 Compression load deflection, 10%, 5 ll pounds per square inch I (ASTM D 575-46, Method A) 269 322 1IO-C11=-CH20 01-120 Compression set, \C S (ASTM D 39541, Method B) 9.8 10.5

II0CH:CH2O CHzClIzN Results comparable to those in the table, supra, are 1'{ obtained using other compounds of this invention.

The new compounds of this invention are also useful as corrosion inhibitors for aqueous acidic systems. 

